Whether to make our own meal or eat food prepared by others is a common dilemma. In the natural world, the dine-in vs. take-out dilemma plays out differ-ently: do organisms make their own food by means such as photosynthesis, or rely on consuming “pre-made” organic compounds for sustenance? Organisms typically do one or the other, being either autotrophs or heterotrophs. Plants and most algae photosynthesize, while animals consume premade organic material through eating plants or other animals. However, many microbes known as mixotrophs get the best of both worlds by utilizing both trophic strate-gies. Mixotrophy may be either faculta-tive or obligate for one or more of the trophic modes. Organisms can also be “functional” mixotrophs by means of using other organisms to produce energy for them, such as in the case of plastid thieves and their so-called “klepto-plasts.” Because of the diversity of mi-crobial life, an example of pretty much any of these combinations can be found somewhere on Earth.

Standard "cookbook" laboratory activities that are used to teach students the optimal physical growth conditions of microorganisms should be modified so that they more effectively foster student's higher order cognitive skills and attract student interest. This paper describes a laboratory activity that engages students in an inquiry-based approach to studying the physical growth requirements of microorganisms. In this activity, students design and implement an experiment to obtain pure cultures of specific microorganisms, with distinct growth properties, that are provided to them in a mixed culture.

The purpose of this essay is threefold: to give an outline of the life and the various achievements of Theodor Escherich, to provide a background to his discovery of what he called Bacterium coli commune (now Escherichia coli), and to indicate the enormous impact of studies with this organism, long before it became the cornerstone of research in bacteriology and in molecular biology.

This tip describes a simple laboratory exercise to assess the microbial contamination of mobile phones, and suggests extension work that enables additional exploration of the topic. At its most basic, it is suitable for the school classroom; more advanced development of the suggested activities are suitable for undergraduate project work.

The first definitive description of neonatal meningitis due to “yellow-pigmented Enterobacter cloacae” was in 1961, and it was followed 4 years later by a similar description. Biogroup 15 was the most distinct and had four distinguishing characteristics. It also was the only biogroup that fermented a-methyl-D-glucoside. At the time, it was suspected that Enterobacter sakazakii really was a new genus with at least two species. However, as there was a wait in the laboratory to do another round of DNA-DNA hybridization experiments, the original paper in 1980a had to go with the hybridization data for only five E. sakazakii strains. The paper of 1980a and the publications it cited gave several early insights on human infections and the epidemiology and ecology of hospital infections. The need for a foundation to further research of E. sakazakii came from several recent discussions and events. Input on the foundation’s mission will be solicited from the public, industry, physicians, microbiologists, other scientists, government and regulatory agencies, and from anyone else who wishes to give input.

This chapter is the first of the biography that tells the story of how a bacteriologist’s quest for the mechanisms of disease turned into a philosopher’s search for the meaning of health. René Dubos, taking frequent refuge on his land that he gradually established living connections to the soil and found a lasting satisfaction from the hard physical work the land demanded. The land gave new strength to his science and writing. As trees grew, ideas matured and his transition from soil microbiologist to philosopher of earth became more inevitable and more assured. The chapter talks about his early childhood, discusses his career approach in soil science, and his entry in the new field of soil microbiology. Using direct techniques, Serge Winogradsky, one of the founders of soil microbiology, made three important discoveries: each type of soil contains an indigenous biota, each sample of soil harbors innumerable types of microbes, and many soil microorganisms could not be cultivated by any other means. Several qualities from his early work characterize Dubos’ approach to future research.

Madeleine Jolit provides information on her experience in lab. The author and her group were isolating mutants and carrying out the first assays of amylomaltase and galactosidase. Jacques Monod invented the “bactogène,” an apparatus designed to maintain “a continuous process for the cultivation of microorganisms, involving continuous and simultaneous addition of nutrient medium into, and removal of culture liquid from a fermenter." Monod was busy setting up his new service, welcoming and taking care of his students both in the lab and at the university. He would work only occasionally at the bench now, participating in some permease assays, having a look at the petri dishes. The author is thankful to this unique atmosphere which everyone in her group had created. She had known many labs in France and abroad, but had never seen anything like the one she had worked at. In that sense, she and her group had been very lucky.

In this chapter, the author relates his experiences as Jacques assistant at the laboratory. The core of the question in those days (1948–1950) was to understand why there was an increased rate of enzyme formation upon addition of the substrate (adaptation) or a diauxic inhibition. The working hypotheses in the lab were that “many different enzymes may stem from a common precursor or pool of precursor molecules” and that the “master pattern configuration determining the specificity was not the enzyme itself but a pre-existing self-duplicating unit (the gene).” On April 11, 1949, the author and Jacques spent the day at 37№C to give birth to the “bactogène.” The results were encouraging and Jacques wrote in his notebook the theory which was the basis of the bactogène.

Perhaps Koch's greatest contribution to the development of bacteriology and microbiology as independent sciences was his introduction of a pure culture technique using solid or semi-solid media—soon known throughout the world as "Koch's plate technique" (Plattenverfahren). The basis of the plate technique is the development of isolated colonies on solid or semi-solid surfaces. Koch began the section on pure cultures with this solidly based statement: "The pure culture is the foundation for all research on infectious diseases." In his paper, Koch then turned to an explanation of the rationale for the plate technique that he had developed. Koch's work described in this paper was an amazing tour de force, one rarely duplicated in the scientific world. Koch realized immediately that the plate technique had many uses besides its value for the isolation of pure cultures. One final extension of the plate technique should be mentioned here: the development by Richard J. Petri of a special plate for agar or gelatin culture. The far-reaching implications of the Koch plate technique are obvious to all bacteriologists. When we contemplate this miracle now, we might wonder why the plate technique had not been thought of earlier. Certainly one o f the major reasons was that earlier workers lacked the will to develop new techniques. As long as one had doubts about the germ theory o f disease, there was little motivation for thinking up new techniques.

Less than two weeks after Robert Koch returned from his triumphant success in London, he began his research on the etiology of tuberculosis. At the time Koch began his work, one-seventh of all reported deaths of human beings were ascribed to tuberculosis, and if one considered only the productive middle-age groups, one-third of the deaths were due to this dread disease. Tuberculosis had been recognized as a specific disease entity since antiquity. Although tuberculosis of the lungs does not seem to have been common in Egypt, pulmonary tuberculosis (also called phthisis) was well recognized by the Greeks, and extensive descriptions can be found in the writings of Hippocrates and others. Another major form of tuberculosis was subsequently recognized, miliary tuberculosis, in which the lesions are tiny nodules disseminated throughout the body. Koch's aim, from the beginning, was the demonstration of a parasite as the causal agent of tuberculosis. To this end, he employed all of the methods that he had so carefully developed over the previous six years: microscopy, staining of tissues, pure culture isolation, animal inoculation. As is now well known, Mycobacterium tuberculosis, the tubercle bacillus, is very difficult to stain with conventional bacteriological stains because of its extremely waxy nature. The properties of the tubercle bacillus make it extremely difficult to work with, and it is remarkable that Koch achieved such quick success in his experiments.

To symbolize the magnitude of Robert Koch's discoveries, we need only mention that shortly after the completion of his studies on anthrax he electrified the world by discovering the microbes responsible for cholera and for tuberculosis—two of the most destructive enemies of humankind. In reality, several veterinarians and physicians had suspected long before Pasteur and Koch that bacteria were responsible for anthrax. The three decades that followed the original studies on anthrax saw the discovery of many other bacterial agents of disease by Pasteur, Koch, their associates, and their followers. The great theoretical advance in the germ theory of disease was to be made by Pasteur himself when he discovered that disease can be caused by agents so small as to be invisible under the microscope and able to pass through filters, and so peculiar as to fail to grow in the ordinary culture media of the bacteriologists. These agents of disease are now known as filterable viruses or simply, viruses. The new discovery came from the study of rabies. The general symptoms of rabies suggested that the nervous system was attacked during the disease. Nerve tissue seemed to be an ideal medium for the virus of rabies, and to fulfill the condition of selectivity, which was the foundation of the cultural method.